Retreatment of Hepatitis C Virus Among People Who Inject Drugs.

BACKGROUND Hepatitis C virus (HCV) is a leading cause of infectious disease death in the United States. Although highly effective direct-acting antiviral (DAA) regimens are well established, retreatment among people who inject drugs (PWID) has not been sufficiently studied. This study assessed DAA retreatment outcomes and associated factors. METHODS We performed analyses of longitudinal data from the HERO Study, a US-based multi-site pragmatic randomized trial conducted in 8 states to evaluate effectiveness of 2 HCV care models among DAA treatment-naïve PWID in opioid treatment programs and community clinics. After initial HERO Study sofosbuvir/velpatasvir (SOF/VEL) treatment, participants eligible for retreatment were identified, from 15 September 2016 to 13 September 2021. This analysis characterizes participants who either did not achieve sustained virologic response (SVR) or were reinfected with HCV post-SVR. We compared categorical variables using Fisher exact test and continuous variables using the Welch 2 sample t test for means and an asymptotic 2-sample Mood median test. RESULTS One hundred four participants were identified as eligible for retreatment. Less than half, 43 (41.3%), initiated retreatment. Among the 25 who initiated retreatment and for whom SVR results were available, 24 achieved SVR (96%). Participants who did not achieve SVR initiated retreatment more promptly than participants reinfected post-SVR (respectively, 471 vs 784 days on average, P < .001). CONCLUSIONS After reinfection or not achieving SVR with the first DAA regimen, retreated PWID achieved higher SVR rates than with initial DAA treatment. To attain HCV elimination and benefit individual and public health, assisting PWID with accessing prompt retreatment is crucial.